Posted By Robert Jones
Could anyone advise me on the hazards arising from permanent magnets when the person using the magnet has a bioelectronic device (pacemakers etc) fitted. I have read a paper that suggests a magnetic flux of 0.5 milli Teslas, when in close proximity to the upper torso, could interfere with the operation of a pacemaker. Is this true?

Posted By Garry Homer
Sorry to be late in on this one.

A practical way of dealing with a specific individual's situation is to ask your company doctor to contact the employee's doctor with the aim of contacting the manufacturer of the implant.

The manufacturers are used to this type of enquiry and can issue details of the immunity levels of their device to DC and AC fields in reasonably plain English.

All implants differ and have different immunity levels with the more modern devices being more robust.

A pacemaker will usually default to a steady rhythm but not react to the needs of the body while the external source is present. Once the employee steps away from the magnetic field source, then normal operation will resume unless the magnetic field was sufficiently high enough to damage the device - back to the operating table!

Armed with the device characteristics you can then assess the employee's environment from a sound knowledge base, rather than dealing with generalities.

It is more interesting and a lot more care is needed if the implant is a defibrillator as you do not want to try and jump start the heart if it is doing ok on its own!

This is one type of assessment report that is poured over a few times before you sign it off!

No matter how careful you have explained everything you have done and shown the additional safety factors you have included in your assessment it is not unusual for the company doctor, who signs the employee off as being fit for work, to add a few more safety factors or restrictions of their own.

Risk mitigation based on fact not guesswork.

Garry